1. Field of the Invention
The present invention relates to a oxygen production process using three-stage pressure swing adsorption plants.
2. Description of the Related Art
At present, patent literatures and documents in relation to a method of making pure oxygen from air with three-stage pressure-swing adsorption technique have not been published at home and abroad. All of methods of making pure (or enriched) oxygen from air known in the art adopted the two-stage pressure-swing adsorption device. For example, CN1252322A, U.S. Pat. Nos. 4,190,424, 4,595,083 and 5,395,427, etc. In the art, the concentration of oxygen was higher in the adsorption tower before performing desorption-blowdown step. The investment and the electricity consumption of the whole oxygen-making device were very high because the recovery of oxygen was low.